A battery has a characteristic in an easy application according to a product group, excellent preservability, a high energy density, and the like. Further, the battery attracts attention as an energy source for improving an environmentally-friendly characteristic and energy efficiency in that a by-product according to the use of energy is not generated, as well as a primary advantage in that it is possible to decrease the use of fossil fuel.
Because of this, the battery is universally applied to a portable device, an electric vehicle (EV), and an energy storage system (ESS), and serves as a basis in various industries and simultaneously provide convenience to everyday life.
However, the battery may be abnormally driven according to a use environment, and the abnormal driving of the battery causes various accidents, so that it is required to stably protect the battery through careful monitoring and an appropriate control.
For example, when the battery is put in an abnormal environment, such as overcharging, short-circuit, and reverse access, or a life of the battery is exhausted, gas is generated inside the battery by an electrochemical action, and the excessive gas generation causes a swelling phenomenon of the battery.
The swelling phenomenon of the battery may lead to an accident, such as ignition and explosion, as well as life shortening and capacity decrease of the battery, so that there is concern in safety.
Accordingly, the related art presents various technologies for detecting a swelling phenomenon of a battery, and for example, Korean Patent Application Laid-Open No. 10-2009-0131573 discloses an apparatus for cutting power during overcharging of a battery, in which when a swelling phenomenon is generated in a battery, a connection between an electrode assembly and an electrode lead is broken, so that a power connection unit between cells is disconnected, thereby preventing overcharging.
However, in the related art, only when some elements are broken due to the swelling phenomenon of the battery, the overcharging is prevented, so that it is not easy to re-use the battery through regeneration, and a spark generable during the break acts as an ignition source, so that there is a possibility that the spark is another reason of ignition.